1. Field of the Invention
The present invention relates to a method and circuit for converting the image format of n-line, three-dimensional electronic images produced with line polarization into m-line images whose respective, immediately neighboring two lines are respectively polarized in alternation into first and second directions upon viewing, wherein all lines polarized in the first direction are employed for the presentation of a first sub-image and all lines polarized in the second direction are employed for the presentation of a second sub-image.
2. Description of the Prior Art
The line polarization method utilizes the interface method in television transmission. In the interface method, a first and a second field are always transmitted in alternation, these being combined in a comb-like fashion to form an image.
Two images, one for each of the eyes of the person, are needed in three-dimensional viewing, these being offset relative to one another in conformity with the respectively different viewing angle of each eye relative to the motive. The two fields in the television transmission can respectively present one of these images, whereby one field is polarized in a first direction and the other field is polarized in a second direction. This, for example, can be achieved with a polarization filter on the field pane of the image presentation device that polarizes the individual lines into the one and other direction in alternation. When this is the case, one can view three-dimensionally with corresponding eyeglasses that filter out the one image for the one eye and the other image for the other eye.
The different resolution standards in which images are transmitted represent a current problem. Known resolution standards are, for example, 625 lines in the PAL transmission method, 1250 lines in the HDTV transmission method and 575 lines in the PAL plus transmission method. When an electronic image presentation device is designed for one of these standards and this same image presentation device is also prepared to polarize the individual presentation lines into the one and other direction in alternation for three-dimensional image presentation, a three-dimensional image transmitted in a different resolution standard can no longer to presented. The reason for this is because allocation of polarized lines of the image presentation device and the transmitted fields no longer coincides.
The publication by Jugen Ost, “Bildfernsprechen, kompatibel mit de Fernsebrundfunknorm,” In Radio Mentos Electronik, 1975, No. 5, pages 194-196, discloses a method for converting the image format of 313-line electronic images into 625-line images by repeating every line. No measures are addressed in order to be able to produce three-dimensional images in the conversion with line polarization.
German patent document DE 32 34 557 C2 describes a “1250/100/4:1 standard” that is intended to enable HDTV and 3D reproduction. This standard is based on the fact that frames are respectively composed of four sub-images that are written on a color television screen in mutually offset grids with a sub-image frequency corresponding to twice the power supply frequency.
It is therefore an object of the invention to specify a method and circuit arrangements for the conversion of the image format of three-dimensional electronic images produced with line polarization.